10 Things That Your Family Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the perfect cup of coffee. What exactly is it?

To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Group Head

The group head is the portafilter you insert when brewing espresso. It is responsible for dispersing the water into the portafilter, and controlling the pressure that results from the extraction. There are a variety of group heads each with their own advantages and disadvantages. Some are focused on temperature stability, whereas others on pre-infusion features, and others are designed to control the lever. There are some that come with a range of features, such as the E61 that is the classic choice among many baristas due to its ability to offer multiple benefits in one package.

As you can see from the image above, the group head is fitted with a variety of notches. It is possible to place your portafilter inside these notches, and then twist the head to secure it. A gasket of rubber is situated within the notches to create a seal as you insert your portafilter. The notches permit the precise placement of the portafilter. This is crucial to ensure a consistent extraction.

The group head not only lets you to place your portafilter easily however, it also keeps the temperature at a constant level. It does this by circulating hot water through the brew basket and around the portafilter, ensuring that it is always at the right temperature for extraction. It is crucial to keep in mind that even a small differences can make the distinction between a decent and a great espresso.

The Pump

The motorized pumps in rotary espresso machines provide the nine atmospheric bar pressure required to extract espresso. This differs from manually operated piston machines that employ levers. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically more affordable and last longer than piston-driven machines. However, both types of machines can deteriorate due to overuse and inadequate cleaning. Pumps are also more complex mechanically, which can increase the cost of even the simple models.

Some espresso machines make use of steam pressure instead of a pump for brewing espresso. The drawback is that the same boiler that produces steam also increases the temperature of water to the point of boiling and can result in over-extraction. In addition the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines use an rotary or a vibration pump. A vibration model employs a rotating disk to generate pressure, whereas a circular model pushes hot liquid through the ground at a rapid speed. Both machines produce great espresso however rotary machines tend to be more quiet, durable and less likely to fail.

The Boiler

The boiler is used to heat the water to a temperature that is ideal for extraction. The steam that is produced gets to the portafilter which is the container that holds the espresso coffee grounds. The steam is then channeled into the cup. During this process, the steam creates pressure that pushes through the grounds of the coffee. This produces a layer of crema on top. This is a sign of a good espresso.

There are three types of espresso makers. They differ in the type of pump they employ and how hot the coffee is. There are also different ways in which the brew can be controlled, as well as the dimensions of the cup the machine is capable of making.

The first espresso machines were steam-types. They utilized one boiler to create steam and brew, however, the pressure they could produce was very low - just two bars of atmospheric pressure maximum. This resulted in the coffee tasting burnt and bitter. This is why the Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most commonly used espresso maker is a semi-automatic machine with an electric pump. This is what people envision when they think of an espresso machine. With a semi-automatic machine you must grind the beans and tamp them by hand. The pump is able to regulate the flow of water and pressure. This is a great compromise between the human touch and the mechanised quality.

The Filter

Espresso machines usually use filters that separate the coffee grounds from the hot water. The filter is also a vital part of the machine's temperature control, since it helps to prevent overheating.

It also aids in flavor, as a filter allows for a more prolonged bloom phase. This helps the beans let their nuances out and provides an opportunity for better extraction.

It is important to keep in mind that even the best filter can make a bad cup of coffee. The quality of the beans and the extraction process are still very important.

This is where the magic happens. It's what makes espresso taste good. The grouphead, also referred to as the brew head, is the place where the portafilter (the thingy you put the coffee grounds into) is located when you're making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight tank to produce steam, which is then pushed through the grounds under high pressure. These types of machines are generally less expensive and easier to maintain than pumps-driven models. They are however limited to create the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machine small machines powered by a compressed air compressor have become increasingly popular. They utilize an air compressor to force hot water through the ground and are more mobile than steam-driven electric buy espresso makers machines.